SQL Fundamentals
Why Your Benchmark Measured the Cache
A query run five times in a row reports the speed of memory, not of the system. Which layer answered the request is the first thing to establish.
· 3 min
tag
#performance
Articles tagged “performance” on SQLPress — 3 in total.
3 articles
PostgreSQL
EXPLAIN, ANALYZE, BUFFERS: Three Different Questions
Which variant you ran decides whether the numbers in front of you are the planner's estimate or a measurement, and whether the pages came from cache.
· 4 min
SQL Fundamentals
N+1 Queries: What the ORM Is Actually Doing
One query for the list, then one more for every item in it. The cost is per statement, which is why the profiler shows a fast database and a slow request.
· 3 min